English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Tantalum slag is a type of high-grade tantalum resource with great recovery value. In this paper, a low fluorine process, including alkali pressure decomposition, low-acid transformation, solvent extraction, and crystallization, is proposed to recover tantalum and prepare potassium fluotantalate. First, some tantalum slag underwent alkali pressure decomposition, and the optimal decomposition conditions were obtained under a reaction time of 2 h, oxygen partial pressure 2.5 MPa, liquid–solid ratio 4:1, basicity 40 wt.%, and temperature 200 °C. Under these conditions, the decomposition efficiencies of Ta and Nb were 93.62% and 95.42%, respectively. X-Ray diffraction (XRD) and scanning electron microscope (SEM) were used to detect the main phase of the decomposition residue and showed that it was mainly sodium tantalate. With the increase in oxygen partial pressure, the particle size of decomposition slag gradually decreases and becomes loose. Second, the alkali decomposition residue was subjected to low-acid leaching to obtain fluorine tantalate and fluorine niobate, and the leaching efficiencies of tantalum and niobium were more than 99%. Last, the low-acid leaching solution was subjected to solvent extraction and evaporative crystallization to prepare potassium fluotantalate. The results showed that the tantalum extraction rate and tantalum and niobium separation factors were above 94% and 200, respectively, and the purity of potassium fluotantalate met the requirements of commercial products. Compared with current industrial practice, the consumption of hydrofluoric acid was greatly reduced, and the recovery rate of tantalum was increased.

Recovery and Preparation of Potassium Fluorotantalate from High-Tantalum-Bearing Waste Slag by Pressure Alkaline Decomposition